$B$-meson light-cone distribution amplitude from the Euclidean quantity

以史蒂文·温伯格精神构建的粒子欧几里得有效理论

Euclidean Effective Theory for Partons in the Spirit of Steven Weinberg

本文提出用等时欧几里得关联子替代光锥关联来表述粒子物理，从而通过格点QCD模拟直接计算精度可控的x分布，并以大强子动量作为自然截断消除光锥发散，体现了温伯格有效场论与威尔逊重整化群的思想。

夸克Schwinger-Dyson方程的光锥表示

Light-cone representation of the quark Schwinger-Dyson equation

我们用光锥方法求解夸克传播子的Schwinger-Dyson方程。我们展示了如何使用这种方法可以用来解决方程以外的类空间区域，其中一个通常是限制与通常的欧几里得空间的方法。我们在朗道规范下工作，并使用胶子传播子的红外增强模型，包括瞬子效应，以获得禁闭和真空凝聚。与我们的模型，合理的适合已知的数量，从而在光锥夸克传播子，可用于强子物理在所有的动量转移。

Thermal Heavy Quark Self-Energy from Euclidean Correlators

Brambilla, Escobedo, Soto, and Vairo have derived an effective description of quarkonium with two parameters; a momentum diffusion term and a real self-energy term. We point out that there is a similar real self-energy term for a single open heavy flavor and that it can be expressed directly in terms of Euclidean electric field correlators along a Polyakov line. This quantity can be directly studied on the lattice without the need for analytical continuation. We show that Minkowski-space calculations of this correlator correspond with the known NLO Euclidean value of the relevant electric fiel…

Evolution of the $B$-Meson Light-Cone Distribution Amplitude in Laplace Space

The $B$-meson light-cone distribution amplitude is a central quantity governing non-perturbative hadronic dynamics in exclusive $B$ decays. We show that the information needed to describe such processes at leading power in $Λ_{\rm QCD}/m_b$ is most directly contained in its Laplace transform $\tildeϕ_+(η)$. We derive the renormalization-group (RG) equation satisfied by this function and present its exact solution. We express the RG-improved QCD factorization theorem for the decay $B^-\toγ\ell^-\barν$ in terms of $\tildeϕ_+(η)$ and show that it is explicitly independent of the factorization sca…

UHE Neutrinos: Fusing gluons within diffraction cone

Currently available estimates of the gluon-fusion effect in ultra-high energy neutrino-nucleon interactions as well as in DIS on protons suffer from uncertainty in defining the scattering profile function $Γ(b)$. Indeed, the area, $S$, in the impact parameter space populated with interacting gluons varies by a factor of $4 - 5$ from one analysis to another. To get rid of uncertainties we specify the dipole-nucleon partial-wave amplitude $Γ(b)$ which meets the restrictions imposed by both the total dipole-nucleon cross section and the small angle elastic scattering amplitude. The area $S$ becom…